1. Field of the Invention
The present invention relates to organic light-emitting diodes and light source devices including the organic light-emitting diodes.
2. Description of Related Art
JP-A 2003-86353 discloses a conventional art. The purpose of the conventional art is to provide a transparent substrate which can improve light extraction efficiency of organic electroluminescence (EL) elements at a low cost, and by using this, to provide organic EL elements with higher light extraction efficiency. The conventional art relates to an organic EL element in which: light-condensing structures (microlenses, microprisms, etc.) are disposed between a transparent substrate and a transparent electrode; and a light-condensing layer flattened with transparent resin having a higher refractive index than that of the light-condensing structures is provided.
The conventional art also discloses a method for manufacturing transparent substrates for organic EL, comprising the steps of: applying a transparent resin on a transparent substrate for organic EL; pressing the transparent resin against a member having a surface shape of a casting mold for the light-condensing structures and hardening it to form the light-condensing structures; further applying another transparent resin with a higher refractive index than that of the transparent resin on the substrate; and pressing the another transparent resin against a member with a flat surface and hardening it to flatten it.
In the conventional art, unfortunately, since reflection occurs on the interface between a transparent resin layer and an encapsulation glass in an organic light-emitting diode, there is a problem that is difficult to significantly improve light extraction efficiency.